1. Field of the Invention
The subject invention is in the field of tools for installing fasteners, more specifically tools for installing blind fasteners, so-called because they can be installed from one side of the work material into which they are installed without need for tooling or manual assistance on the opposite side. More specifically, it relates to tools for installing rivets which are fixed in place by (1) inserting the head end of the rivet assembly through the hole into which the rivet is to be installed and then (2) while the rivet is held in place, applying tension to the shank of the assembly. The rivets are designed so that the tension first causes swelling of the head end on the blind side of the work material and second, causes that portion of the shank provided for installation purposes only to break free from the rivet. The swelling holds the rivet in place. The point at which the shank breaks off is determined by a necking down of the shank diameter.
2. Prior Art
The prior art in this field is profuse. However, the subject improved features have been applied to a specific commercially available rivet installation tool and, therefore, that tool constitutes the prior art of immediate interest. The tool is model PH2001, manufactured by Gesipa, G.m.b.H., Walldorf/Frankfort, West Germany. A print of a sectional view of this tool is attached.
Two problems have been found with the tool in the course of its use and these problems have led to the subject invention. In regard to the first problem, in the use of such tools the rivet assembly is inserted shank first into the head of the tool and then the tool is maneuvered into the position for installation of the rivet. It has been found that the rivets often fall out of the tool in the course of the maneuvering. This causes serious loss of time, inconvenience and possibly safety hazards if not enough care is taken in finding and retrieving the dropped rivet assemblies. Lost assemblies can interfere adversely with other mechanisms, electrical systems and the like.
In regard to the second problem, related to the first in the results it produces, is that the shank portions broken off in the installation procedure are ejected from the head of the tool. In instances where installation space allows, these shanks are caught and collected in a container provided with and attached to the tool. However, the requirement for the space for the container has been found to seriously limit the utility of the tool, thus presenting the problem of preventing the ejection of the shanks while not complicating their removal from the tool head at the user's convenience. To summarize, the problems leading to the subject invention were retention of the rivet assembly in the installation tool while the tool is maneuvered into each operating position and prevention of ejection of the expendable portions of the shanks, using a minimum of space in order to optimize accessibility of the tool to use locations.